The implantation of 20% Ge-doped silica with MeV Si or Ge ions has been used to produce singlemode channel waveguides. The germanosilicate film was grown by plasma enhanced chemical vapour deposition. For implantation with either Si or Ge ions, the attenuation loss was measured as 0.15–0.25 dB/cm at 1300 nm and 1.5–1.8 dB/cm at 1550 nm.